Intracellular Bacteria and Spirochetes Flashcards
What are the four major intracellular pathogens?
- Chlamydia and Chlamydophila
- Rickettsia
- Erchlichia
- Coxiella
What are the three notable spirochetes?
- Treponema
- Borrelia (lyme/ relapsing fever)
- Leptospira
Chlamydia and Chlamydophila are obligate ____________. Because of this, how must they be grown in culture?
Obligate intracellular parasites.
When growing them in culture, you must grow them on embryonated eggs or tissue cultures
What is unique about the cell wall of chlamydia?
It lacks peptidoglycan
What virulence factors is used by chlamydia?
LPS
Why is chlamydia an obligate intracellular pathogen?
Because it cannot synthesize ATP so it relies on the host
What are the three main strains of chlamydia?
- Chlamydia pneumoniae
- Chlamydia psittaci
- Chlamydia trachomatis
What disease is associated with chlamydia pneumoniae?
pneumonia transmitted person-to-person
What disease is associated with chlamydia psittaci? Who is most likely to get this infection?
Pneumonia.
The pathogen is found in birds (parrots specifically) so bird owners are more likely to get this
What disease is associated with chlamydia trachomatis?
- STD causing urethritis, cervicitis, prostatitis and PID
- neonatal disease
- ocular disease in developing countries
What is the most common bacterial STD in the US?
chlamydia
What is the leading cause of blindness worldwide?
Chlamydia trachoma
Describe the life cycle of trachoma for spreading ocular disease in developing nations.
- flies carrying the bacteria land on childrens eyes and feed on discharge
- Caretakers of the children acquire the bacteria
- Flies breed in human feces and spread the disease to other
Describe the gram staining, shape and structure of Rickettsia.
It is a small pleomorphic coccobaccilli that has the structure of a gram negative bacteria but does NOT strain with gram staining
What type of bacteria (gram neg or gram pos) has a structure similar to Rickettsia? What is the difference?
Rickettsia has peptidoglycan and LPS similar to gram negative but they do not stain with a gram stain.
Rickettsia is an obligate __________________ so when culturing it needs to be grown on ______________.
obligate intracellular pathogen so needs to be grown on egg yolks or tissue culture
What cell do Rickettsia replicate in?
they replicate in endothelial cells of blood vessels (damaging the vessels)
What is the vector for Rickettsia? How many species are there?
The vector is arthropods each with specific mammalian or avian reservoirs and specific geographical distribution
What are the two main types of Rickettsia that affect humans?
- Rocky Mountain Spotted Fever
2. Typhus
What is the main reservoir of Rickettsia associated with RMSF?
What area of the country has the highest prevalence?
What is the peak seasons?
It was first isolated in rocky mountains (hence the name), but it is most prevalent in the southeast.
The main reservoir is rodents and it peaks in spring/summer
How long is the incubation for RMSF and what does the person first present with?
How does the infection progress?
It incubates for a week when the person will start feeling fever, malaise, headache.
After a week they develop a rash (INVOLVING PALMS AND SOLES OF FEET)
What symptom of RMSF tells you that you are “too late”?
What is the mortality rate?
the rash involving palms and soles of feet. It is a week after the infection,
Mortality is over 10%
How is Rickettsia that causes epidemic typhus transmitted?
Via human body louse
Where would one likely see Rickettsia prowazekii? (rickettsia that causes typhus)
In areas where there is poor hygenic conditions
What is the case fatality of epidemic typhus?
over 25%
Describe the shape of Erlichia and Anaplasma.
Small cocci
How do Erlichia and anaplasma stain of the gram stain?
They do not, but they stain with Giemsa and Wright stains
Are erlichia and anaplasma structurally more like gram postives or gram negatives?
They are more like gram negatives because they have dual membrane, but they lack peptidoglycan and LPS.
Erlichia/anaplasma and Rickettsia are both similar to gram negative bacteria, but in different ways. How is each group similar to G-?
Erlichia/Anaplasma- have dual membrane but lack peptidoglycan and LPS
Rickettsia- no peptidoglycan but have LPS
Describe the growth pattern of Erlichia and anaplasma?
They grow in morulae (clusters like mulberries)
Where do erlichia chaffeensis grow?
What does this cause?
Monocytes causing human monocytic erlichiosis
What is the vector of erlichia chaffeensis?
the dog tick and lone star tick
What three states have the highest incidence of erlichia chaffeensis?
Arkansas, OK, Missouri
What cells are infected by anaplasma?
Granulocytes causing granulocytic ehrlichiosis
What is the vector of anaplasma phagocytophilum?
Ixodes tick (same for lymes disease)